“The rule of thumb is that if a player has a team on his no-trade list, it makes it less likely,” one rival general manager says.

Greinke, 27, has 15 teams on his no-trade list. The Rangers, Braves and Reds are among the clubs with possible interest in him that aren't on the list, sources say. Those teams would face no such obstacle in trading for the Royals ace.

The Jays possibly could land Greinke if they were willing to part with right-hander Kyle Drabek, outfielder Travis Snyder and another minor leaguer or two, according to the Toronto Sun.

Such a package would intrigue the Royals, sources say. But the Jays might not be ready to break up their emerging core of young pitchers to take a run at the postseason, even if they could persuade Greinke to join their club.

Greinke's signed for two more years at $13.5 million per season. He'll become a free agent after the 2012 season.